Every now and then during your flight training pieces of knowledge and expereince fall together only to open up a door to new questions. This article is one of those questions I had when I was studying weather – Just how much does temperature and pressure impact the altitude your aircraft says you are at? We are given baro readings by ATC which are based AT the airport, not in the sky where we are at. This works fine so long as everyone is using the same reading, like 29.92 at 18,000 and above. But in our airspace different planes are using different settings, so we are therefore flying at slight or not so slight variations in altitude. Read on to learn more about Austin’s live experiment.

Your Altitude is Wrong

by Austin Meyer, owner and developer of X-Plane, keeps a personal blog called Austin’s Adventures.

OK so I am working on the VP-400, and artificially-intelligent avionics package that continuously considers power-off glides to every airport within gliding range and will take your airplane down to the best runway within gliding range for a power-off landing at the press of a single (red!) button.

One of the things I need to know to make this system work is how high you are, and how fast you are descending.

You can tell that from an altimeter and a vertical-speed indicator, right? Oh, you are SOOOOOOOOOOOOOOOOO wrong.

All altimeters and vertical speed indicators are based on pressure, and change of pressure with altitude! It is this change of pressure as you climb that winds up your altimeter, and how fast this pressure is changing that winds up your vertical speed indicator.

But here is an interesting thing about the atmosphere: While non-standard PRESSURE is always reported to us in every ATIS broadcast, any non-standard LAPSE-RATE OF PRESSURE WITH ALTITUDE is NEVER reported! I mean, listen to ATIS! Do they say: “Altimeter 29.85”, or do they say “Altimeter 29.85, with a lapse of 0.92 inches for the first 1,000 ft, then a laps of 0.90 for the next 1,000 ft, then a lapse of 0.88 for the next 1,000 ft…” and so on for the entire climb up to the flight levels?

Of course, they ONLY give the pressure, and NOT the change in pressure with altitude!

…And just as the pressure varies from standard on every flight (thus your need to enter a pressure into your altimeter) the pressure LAPSE RATE ALSO varies on every flight… but they never TELL you that, do they? And since they never correct for the non-standard pressure lapse-rate that we see every day, our altimeters get increasingly in-accurate the higher we climb, since we are climbing into air of increasingly-unknown density, since the lapse-rate WILL vary from day to day.

And, if the ALTIMETER is wrong, isn’t the VERTICAL-SPEED INDICATOR wrong as well, since it clearly will be affected by the pressure change with altitude, since that is exactly what the VSI measures? (The VSI fluctuates based on the rate of change of pressure as you climb or descend! If that rate of change of pressure is different than expected because the pressure change across altitude is different than expected, then the VSI will surely be wrong!)

So, writing my runway-seeker software, I needed to understand whether these pressure-based instruments found some way to be correct, or if they were wrong, and by how much. This would require a high-altitude test-flight in my (non-pressurized) airplane.

So, on a very hot South Carolina afternoon, it was off to 428X, where the tower controller was a bit surprised to see this little propeller airplane file IFR for FL250 (25,000 ft). He simply could not resist asking: “Just how high does that little thing GO?” This is actually a somewhat complex question that I will get to below.

So, before take-off, with minimum fuel to complete the mission on board (minimum fuel to maximize my climb abilities! Remember, the fuel in 428X can weigh a lot, with 108 gallons possible in the tanks!) my pressure-based altimeter (on my G-1000, and backed up by a static-port-based backup) correctly indicated 220 feet… within fifteen feet of the official airport elevation of 236 feet… perfect! As well, the GPS altitude on the MFD indicated 215 feet.. within five feet of the pressure-based altitude! PERFECT! With my IFR plan in place and a take-off clearance, it was full power down the runway in 428X, air conditioning ON to combat the hot, humid, sticky, 95-degree summer afternoon of South Carolina. Craft smartly airborne, I retracted the flaps and quickly set up for a lean-of-peak climb at 16 gallons per hour. Now this is interesting: At full-rich mixture at full-power, 428X burns a staggering FORTY gallons per hour!!! That is the full gas-tank in your car in maybe 20 minutes. For this reason, I always climb at lean of peak, max-lean-cruise power, and burn only 16 gallons per hour, getting maybe half the climb-rate, but the same forward speed and one third the fuel burn! Today, I set my lean-of-peak climb throttle, prop, and mixture, and eased up into the sky at maybe 700 feet per minute, setting up for the half-hour-climb to 25,000 ft to measure the altitudes and vertical speeds, both true and indicated, at every 1,000 ft from sea-level to 25,000 ft. At first, the data was sketchy because of the turbulence and winds of the low-altitude summer day, but I could still detect some alarming trends: Coming through 3,000 ft on the Garmin PFD, the GPS altitude was 3,200 feet!!! The error, at 3,000 ft, between pressure-based and GPS-based altitude was 200 feet! Lest any reader grasp at the imaginary straws of ‘instrument error’ or ‘GPS being in-accurate in altitude’ I can dis-abuse you of that notion right now! 428X is nearly new, it’s instruments carefully calibrated and tested at every annual by a shop that does not know the meaning of the word “skimp”, and the Garmin and backup altimeters were in PERFECT agreement with each other, and were in agreement with the GPS to within FIVE FEET when on the ground. There was no vague ‘instrument error’ or ‘GPS error’ here: Something ELSE was going on. As I continued the climb, the error between the pressure-based and GPS-based altimeters continued to steadily increase. The controllers had me change heading from time to time to avoid airspace as I meandered upwards, and I kept entering the latest and nearest altimeter settings from the nearest-available airport to keep the barometric-pressure setting in my altimeter as perfect as possible. As I broke though 8,000 ft, the air smoothed out to perfection, and my flight-test data became completely un-affected by bouncy air. As I climber, the error between my altimeter and true (GPS) altitude continued to widen. I was surprisingly busy working with the controllers on changing heading, constantly getting the latest altimeter setting from the nearest airport from the XM-weather in the Garmin MFD, putting on oxygen coming through 8,000 ft or so, and recording the indicated and true altitude every 1,000 ft during the climb. In fact, there were a number of times when controllers would have new frequencies or headings for me and I had to delay the readback to them to finish obtaining the latest altimeter setting or recording the latest climb data.

At 5,000 ft on the altimeter, my GPS altitude was 5,270… a 270-foot error.

At 10,000 ft on the altimeter, my GPS altitude was 10,530… a 530-foot error.

At 15,000 ft on the altimeter, my GPS altitude was 15,750… a 750-foot error.

At 20,000 ft on the altimeter, my GPS altitude was 21,150… a 1,150-foot error!

At this point, both myself and 428X were starting to struggle. Even with my oxygen on, I felt dizzy and light-headed. Was my O2 system malfunctioning? The cylinder head temperatures were departing the green and heading into the yellow, the tremendous heat from the twin turbochargers working overtime in the thin air simply too much for the engine to dissipate in the incredibly hot summer afternoon. Suddenly, the engine stuttered out to near-silence for just a moment and then came back… were the magnetos not remaining pressurized? Was the fuel beginning to vaporize? Suddenly a flashing alarm on the G-1000 caught my attention! Why hadn’t I noticed it earlier? Was I truly suffering from hypoxia? A new frequency-request was coming in from the controllers, the alert on the G-1000 indicated that I need to turn on the vapor-suppression, a pump that keeps the fuel in 428X from vaporizing in thin, hot, air before it reaches the engine, I felt dizzy… but my O2 was surely spurting in oxygen… I could HEAR it! The new controller had a new heading for me to keep me away from aircraft departing Charlotte.. I needed to record the next altitude and error… the engine was getting close to over-heat… I was already lowering the nose to try to speed up and cool the engine more, but it was not enough! The CHT’s continued to increase, and the climb-rate was starting to bleed off to near-nothing… how could I complete my test? I needed to cool the engine to get it’s temperatures back into the green, and get more power out of it to leap to 25,000 ft to finish my test, and there was only way to do that: FULL RICH mixture and FULL power. Vapor suppression ON to give a steady flow of non-vaporized, cool, liquid fuel to the engine, and easing the mixture control to full-rich to BATHE the engine in more fuel than it could actually burn, thus leaving the rest to evaporate in the cylinders and cool the engine, I advanced the RPM and throttle to REDLINE, and the engine surged with new vigor and the climb-rate surged smoothly to 1,000 feet per minute as the cylinder temperatures fell back to the green. I was still dizzy and light-headed and confused, but the airplane was surging strongly upwards, and I was still able to record data every 1,000 feet.

At 21,000 ft on the altimeter, my GPS altitude was 22,200… a 1,200-foot error!

At 22,000 ft on the altimeter, my GPS altitude was 23,200… a 1,200-foot error!

At 23,000 ft on the altimeter, my GPS altitude was 24,270… a 1,270-foot error!

At 24,000 ft on the altimeter, my GPS altitude was 25,290… a 1,290-foot error!

Fuel was now dumping overboard at an alarming FORTY gallons per hour, and my remaining 30 gallons was suddenly starting to look sort of thin. I was now using everything the airplane had, and curtailing my future options as the fuel dumped through the engine to give me the power and cooling I needed to power up through the hot, thin, air. I continued to use the best altimeter setting I could find, violating all rules about using 29.92 in the flight levels, because I needed to use the best altimeter setting to get accurate results from the experiment! My clearance to FL250, though, provided the buffer that I needed to avoid an altitude violation. So how high could 428X GO? At lean of peak, it can barely limp to 25,000 ft, but with full-rich mixture and full power it could easily surge well above 25,000 ft, and surely up to 30,000 ft, but the fuel would be exhausting at an alarming rate, and the pilot may be passed out inside. At 24,000 ft, I decided that was as high as was willing to go, since my clearance was to FL250, and since I was using the most accurate altimeter setting I could find, not 29.92, so there would be some error in my altitude compared to what I was assigned! Thus my need for a 1,000 ft buffer in my clearance to avoid an altitude excursion. Temperatures high, fuel low, pulse-rate elevated, O2 saturation low, I requested a descent back to Columbia. Now it was time for the second half of the experiment: Is the VERTICAL SPEED INDICATOR accurate, or is it just as bad as the altitude? The answer soon became obvious: The vertical speed was PERFECTLY tied to the altimeter. I dialed in a 1,000 foot-per-minute descent, and every 1,000 feet on the pressure-based altimeter took EXACTLY one minute to elapse. I am not exagerating when I say that going from 24,000 ft to 4,000 ft on the pressure-based altimeter took EXACTLY 20 minutes… to within about ONE SECOND. Back at 4,000 ft again, I could breathe, the engine could cool, the recorded data could sit on my pad, and it was with some relief that I landed and taxied in.

So, what were the lessons?

The lessons are:

=>Your altimeter is perfectly accurate at the airport if you enter your barometric pressure correctly.

=>At the cruise altitude of about 8,500 feet or so, your altimeter is off by about FIVE-HUNDRED FEET.

=>At that altitude, it does not matter much that your altimeter is off, because everyone else’s is off by the same amount, and you are far from the airport, and thus landing.

=>The error always seems to be off in the safe direction: You are always HIGHER than you think. Clearly, when they designed the system in 50’s, they designed the altimeters to follow the most conservative lapse-rate we could encounter, so in real-world flying, we are almost-always much HIGHER than we thought, which must be the safest error we can make.

=>The vertical speed indicator perfectly tracks the PRESSURE-based altimeter, not the true altitude, so the vertical speed indicator can be perfectly used to see how much the altimeter will change over time, the ACTUAL climb or descent rate of the plane is actually considerably DIFFERENT… at high altitudes, by 1,290 parts in 24,000, or just OVER FIVE PERCENT.

I don’t know how much this matters to you, but as I design the software for the VP-400 A-I runway seeker, all of the altitudes and descent rates will be computed by GPS, and if the altimeter disagrees with what the GPS says, I will know exactly why.

As many of you know who have been following me, I fly as money allows (and sometimes when I can’t afford it) to maintain currency. I don’t like talking about it much because we all have issues. I’m talking more about it today because I hope that what I DO with my flying will convince others to financially support my endeavour over the next 120 days through Indiegogo.com.

Every penny earned will go towards flying, from G1000 transition training, to commercial and instrument ratings, all of the hours used to reach these goals will help me achieve Mission and Orientation Pilot status in the Civil Air Patrol so that I can serve my community as a volunteer pilot.

Help Me Volunteer More with the Civil Air Patrol

My name is Barry Orlando. I am a recreational pilot, a Civil Air Patrol pilot and father of two living in the Finger Lakes region of New York State. I earned my Private Pilot certificate in October 2007. Three years later in October 2010, I earned my Advanced Ground Instructor certificate. Since then I have wanted to continue my training to earn commercial and instrument ratings, but this has been sidelined due to the economy and rising fuel costs.

I am looking to raise $20,000 to fund commercial and instrument flight training so I can do more with the Civil Air Patrol, such as become a Mission Pilot and an Orientation Pilot for young cadets. If you don’t know much about this fine organization and wish to learn more, may I suggest you visit their site at gocivilairpatrol.com.

My flying and volunteer work revolves around the following areas:

Search and Rescue

Disaster Relief

Humanitarian Services

Air Force Support

Counterdrug / Homeland Security

The Civil Air Patrol does not pay for flight training or pay you to fly. Only specific flights such as real-life emergencies are paid for by the Air Force.

I WISH TO DO MORE…but to do that I need to meet certain hour requirements as a pilot. For example, to be a Mission Pilot, I need 55 hours of additional flight time and at $100 an hour for plane hire, it will cost at least $5500 or subsequently $8500 to fly enough hours to be an Orientation Pilot. As you can see, it adds up quickly just to be in a position to fly these specialized missions. I am hoping to make this a possibility by training for both my commercial and instrument ratings. So I will meet the requirements and have ratings that will allow me to fly in different conditions.

The Impact

Right now, there is a shortage of pilots to fly missions in addition to an aging population of pilots. Higher costs mean less young people are becoming pilots…who will fly these missions?

By reaching my goal I can do the following:

fly critical and potentially life saving missions for the community

fly cadets on orientation flights and introduce them to aviation

fly in less than ideal conditions (emergencies don’t wait for good weather)

help the next generation of pilots in the Civil Air Patrol

become a flight instructor and earn my own way

Any financial assistance would be very appreciated but If you can’t help right now, please spread the word on Facebook and twitter.

On May 21, 2012 I completed my form 5 check ride for the Civil Air Patrol. My check pilot was Roland Zavada and I managed to torment him for 1.7 hours. This flight was not my finest piece of work. I’ve never been fond of check rides because as much as you are pilot in command you have someone who is telling you what maneuvers to do. The good news was that I didn’t fall for the “oh look…there’s deer in the farmers field down there” distraction on downwind. Sterile cockpit…please!!!

2001 Cessna 172S (N927CP)

The plane I used for my check ride was a 2001 Cessna 172S (N927CP) – It’s a nice plane but I only flew it 3 times (5.9 hours) before my check ride, so I guess I might know what I am doing. It matched the 172S in Microsoft flight simulator so I was familiar with the location of gauges and was quick to adapt to it. The GPS is a bit different than what I was use to and I only messed with it a bit as the last part of my check ride.

A form 5 check ride in CAP (Civil Air Patrol) is pretty much the same as any other private pilot check ride. Even though I am a pilot already, CAP requires a check ride before you are cleared to fly solo in their aircraft. By competing the check ride I am now considered a VFR Pilot in CAP and because I have over 50 hours cross country I am also cleared to be a Transport Mission Pilot which allows me to ferry planes and people around as needed for the squadron. As you gain more hours as PIC you can become a Mission Pilot at 175 hours PIC or a Flight Orientation Pilot at 200 hours PIC.

I will be focusing next on flying along on counter drug missions and will be transitioning to a G1000 equipped Cessna 182 as funds allow.

If you care to help me acheive my goals, please let me know. CAP is a volunteer organization and many people like myself pay for our own flying time and the cost of fuel. Only approved missions are funded flights in CAP so the time I’ve spent in the air flying for CAP has been out of my own pocket and not the tax payers. I enjoy serving and hope that other pilots consider the Civil Air Patrol as an opportunity for themselves to server their community.

Well after years of being an active member in my flying club, I needed to suspend my membership due to budget changes. I also haven’t flown there since July of last year and want to change things up and focus more on my role in the Civil Air Patrol.

My promotion to 1st. Lt. was made official today and recently I was approved for CD missions. I am also trying to wrap up my form 5 check ride (if this weather gets with the program) so that I can finally become a CAP pilot, and then hopefully I can move on to become a transport and orientation pilot. The rest is all about building time and confidence to eventually be a mission pilot.

The plus’s are that I will be in newer aircraft and can also transition to a 182 G1000. No flying club has a 182 G1000 around here! And even if they did it would be very costly to operate. The other plus is that I would continue to be around other pilots, under a controlled airspace and piloting at a level that is more than recreational, but not commercial.

The minus’s are that I can’t take non-members up in aircraft, so no family flying here, but that could be remedied in other ways with a check ride here or there elsewhere. That’s about it.

So the focused has changed and I will keep you posted as things happen!

Now that drivers are getting sticker shock at the pump and being told there is nothing that can be done about it, they might start appreciating what we in general aviation have known about for awhile…fuel costs can make or break you.

Right now 100 LL (Low Lead) at Rochester, New York (KROC) is selling for $7.07 a gallon. This price is $3.00 more per gallon than regular unleaded gas. Now if you take $7.07 a gallon and multiply it by 53 gallons to fill up a Cessna 172S, your fuel cost comes out to $374.71 to top off the tank. If you get a fuel burn of 10 gallons an hour you are burning $70.70 worth of fuel every hour you fly, not including the cost of insurance, fees, and maintenance.

As a recreational pilot (like many) who make a modest income (like most pilots & non-pilots) I realize that I won’t get any sympathy from the general non-flying population. However, when planes don’t fly they don’t get serviced (mechanics lose jobs), they don’t get fueled (tax revenue is reduced significantly), facilities fall into disrepair (costs increase) and your local airport starts looking a like an old Wild West ghost town.

Recreational pilots have their financial limits too. Yes believe it or not we do not have bottomless wallets where we can just dig deeper to pay more…and more…and more. Already industry leaders in aircraft manufacturing are re-evaluating the American market and are ready to leap to China (with a Chinese partner) and build aircraft over there. Hawker-Beechcraft is rumored to be close to filing for bankruptcy. The American market is soft and since corporations need to go where the money is (to stay in business), you can expect more Americans…perhaps even you…to lose their highly skilled job.

Now it doesn’t take a rocket scientist…sorry…we are losing them too…to sit up and take notice to what I call “trickle up economics”. This is where you and I STOP consuming products or services due to costs causing what’s known as a recession, or a snowballing recession. As we stop becoming consumers, the industries above us who benefit from our consumption hold back, layoff, re-structure, go bankrupt or go into survival mode and run into the arms of a foreign partner (to their own peril) to stay in existence. This creates a cycle that generates a recession or depression.

Can it get worse?

If you haven’t noticed, the cost of a gallon of regular unleaded is $4.00 a gallon in many places, even though the price of a barrel of oil is $105. It’s interesting because just a few years ago oil at $146 a barrel was creating $4.20 a gallon gas. Given this historical information, as shown in the graph below, it would appear that not only can things get worse than they already are…they can get far worse. Is this part of a bigger plan?

Washington politics are now forcing a cut off of oil supplies from Iran to other countries, creating highly competitive conditions for the remaining supplies of oil. Higher demand on low supply causes prices to increase…the snowball is getting bigger. Higher prices will most likely create a double dip recession. Another recession could be just enough to cripple General Aviation permanently, and if you are expecting a government bailout for Hawker-Beechcraft, my advice is to not hold your breath. Why? Simple…it’s because nobody is paying attention to the frog (General Aviation) in the slowly boiling water and they don’t care.

The question is this…when will common sense finally kick in? The common sense I am talking about is this…when will we stop killing our own economy with the policies we keep putting into place? Our turn-around time is finite. Old pilots and planes do die, so what do we have to do to fill the gap? What’s the plan? How can we bring in more student pilots when we are hit with wave after wave of poor decision making and higher costs?

“The production of too many useful things results in too many useless people.”

– Karl Marx

Policies matter…utopian engineering takes no prisoners. Does the making of fewer useful things result in too many useful people? Not in America! We are already making fewer useful things and higher unemployment…and the exporting of our manufacturing base has been the result.

Here is an important video about economics that even a child can understand. What the video fails to show are the government policies, taxation methods, and low cost global competition that impact businesses and undermine this traditional business model. How well we can adapt to the new business model remains to be seen. Building fewer useful things seems to be creating fewer useful people who can in turn afford the few useful things that we do make, resulting in more useless people.

After a run in with the flu I was finally able to fly my second flight toward earning my VFR Pilot designation with the Civil Air Patrol. With two flights down I am expecting one more before I take my Form 5 check ride.

Today we flew for 2.5 hours and focused on the following:

Short-field Takeoff & Landing

Soft-field Takeoff & Landing

Power-Off Stalls

Power-On Stalls

Maneuvering During Slow Flight

Steep Turns

Clearing Turns and Collision Avoidance

Normal Approaches and Landings

Forward Slips to Landing

ATC Communication

For the most part things worked out well, but strangely enough I was still coming in too high and fast. I am also not trimming much for my landings. I blame myself for not flying enough, for only flying this particular plane twice and for never going nuts on the trim. That’s not to say that I am NOT trimming, I am…but I’m not trimming it fully enough to just let it do its thing.

In the clubs 172 I use to squeak them on almost all the time. In fact I was doing really well compared to my instructor (Sir Trim a lot) – and I mean that with all respect. The result was…with a little or a lot of trim….same result. No big deal.

However since I also fly a Cherokee I got use to understanding the need for speed so we don’t sink too soon. This really meant an extra 10 knots during each phase of landing. I also don’t remember needing a lot of trim…I just keep flying it to the runway like I did with the Cirrus a few times.

So I got out of the habit of dealing with a falling leaf Cessna where 55 to 60 knots doing a short field is no big deal…so long as you keep flying the plane. Now I just need to get my head around this issue more which is why I will be playing with Microsoft FSX and practice landings before I get in the plane again.

On Sunday I took to the skies in the Civil Air Patrols 172 N927CP. This was my first time in this aircraft and the first time in over 6 years of operating from KROC and class Charlie airspace.

Flying the 172 may seem like the main event, but for me the excitement…or as some might say…the anxiety…comes from being at a controlled airport, in controlled airspace and having to listen to what’s going on and doing my part. For pilots who fly into Class C and B Airspace, this posting is NOT for you…but it could be good if you have students.

LiveATC Got You Down?

At some point in your flying you have probably been told to listen to LiveATC at: http://www.liveatc.net/ – to become familiar with ATC communications. And that’s a great thing to do, but because of all the commercial air traffic mingling with private pilots, it doesn’t offer the continuity that you may be looking for in order to learn what to do. That was my experience and frankly it didn’t really make things easier or instill confidence. In fact it probably increased my anxiety because everyone sounded like a fast talking expert (because they are) and there is no separation of the frequencies. In particular, approach and tower frequencies. Frustrating!

So before I leaped into ATC communications cold turkey (and there is nothing wrong with that) I documented and asked questions of CFI’s, commercial pilots and even updated a few documents based on my real world experience (and my own ATC recordings) to create three PDF files of ATC Communication for Private Pilots.

Below are my three PDF files of ATC Communication for Private Pilots starting with setting up a VFR departure from KROC (Rochester,NY) and the VFR arrival back to the airport. So there is 100% continuity from a flight out of and BACK to KROC…which is a Class Charlie airspace airport.

I can’t stress enough how important it is to plan ahead and organize in your head, what you are going to do before you leave and before you come back and talk to approach for permission to land. These documents are not written in long English sentences, but allow you to fill in the blanks and act as a script, except for the KROC frequencies…after all…I did make this for me.

If you want the Excel spreadsheet I used, please let me know and I can email it to you!

If you want to hear a few of my recordings, you can download the .mp3 files shown below. Unfortunately I just don’t want to devote a lot of time downloading and editing mp3 files to find everything that I did, so this is just a taste. Again, pardon my amateurish radio work…at least I was brave (or fool) enough to post a few of mine!

Ever look at ads for aircraft and see a bunch of alphabet soup in the description concerning engine time, overhaul time, total time…etc? So what does 4280 TT; 920 SMOH; 1203 STOH; 1234 LMNOP stand for? To help explain this alphabet soup without going into too many details, I created a list for you to review that was based on a conversation I had with a guy who does annuals. Since I am not mechanically inclined I found this very helpful in understanding just what these ads were saying and NOT saying about an aircraft. BTW…LMNOP doesn’t mean a thing unless we use it for: Low Maintenance No Owner Present – many owners avoid keeping their plane current and legal.

Terms for Hours and Overhaul Alphabet soup!

Below are terms used in aircraft-for-sale advertisements showing the engine hours since the last overhaul were carried out are quoted. Hopefully this information will clarify what some of these terms mean and why it’s important not to confuse them.

Overhaul

Overhaul is a term used by the general aviation industry when an aircraft engine is cleaned, carefully inspected, and repaired or has parts replaced to meet service limits.

An overhaul is an overhaul as per the manufacturers specifications. There is no such thing as a major overhaul, just an overhaul, even though you will see the word “major” used to describe them.

Most overhaul’s are defined by the manufacturer with supporting documentation (usually Service Bulletins) that define what must be done and what parts must be replaced.

If an engine, for example, is advertised as overhauled, you have the right to ask how it was done. Was it done to factory new standards or to factory serviceable standards?

Only the very lower quality overhauls are done to factory servicable standards. It implies that many parts are reused instead of being replaced. This also applies to other components such as magnetos, carbs etc.

TSOH (Time Since Over Haul)

Time Since Over Haul is the number of flight hours since an Overhaul was performed.

TBO or TBOH (Time Between Over Haul)

Time Between Overhauls, an engine manufacturer’s recommended overhaul interval in hours, a rough and not guaranteed guide to life expectancy of an engine before it will need overhaul.

SMOH or TSMOH (Since Major Over Haul)

Since the overhaul process requires the engine to be taken apart, it is typically an expensive process. The value of a used engine decreases if it is close to requiring an overhaul, so used engines (and aircraft) typically list their time since overhaul or TSOH.

STOH (Since Top Over Haul)

Top overhaul is a term used by the general aviation industry when all the cylinders on the engine are overhauled or replaced with new, possibly due to corrosion.

TTSN, TSN, TT (Total Time Since New) or AFTT (Air Frame Total Time)

Total Time Since New is usually an airframe time reference for the total number of flight hours on a used aircraft.

TTAF/E (Total Time Air Frame/Engine)

Total Time Airframe and Engine(s) is usually an airframe time reference for the total number of flight hours on a used aircraft.

I have taken a great deal of time in the last couple of years in examining aircraft ownership for myself. In this update I have outlined just some of the initial research steps involved in getting clarity before there is even a pre-buy inspection. I started down this road because I saw a 1969 Cessna 182 in VERY good condition and really wanted to KNOW WHAT I DIDN’T KNOW in order to sum up an aircraft which would NOT need an overhaul. The research starts out like this…

Use the N# to contact the FAA Registration office for records of ownership (registration) and maintenance. It is cheap ($10.00) and won’t take long to get.

Use the FAA free web site to obtain a list of Airworthiness Directives (AD) notes on the major components of the aircraft (aircraft, engine, prop, mags, carb or fuel injection, vacuum pump, prop governor, etc) that are listed on the TCDS, when you review the maintenance records you MUST be able to SEE PROOF that the AD notes have been complied with. If there is no proof than they will have to be compiled with as per the AD note instructions.

Now you will need information from the owner (real – matter of fact – backed by logbook information).

When was the aircraft last annulled?

When was the aircraft last flown?

What are total times on aircraft, time since overhaul (TSOH) on engine, carb, prop and all accessories.

How is the aircraft equipped? (Garmin 430, auto pilot, turbo charger? etc) Begin looking at industry publications to try and find aircraft prices that are comparably equipped and same time. Use the AOPA listing or other blue book type listings.

In the first step we talked about contacting the FAA Registration office for records of ownership (registration) and maintenance. You may request a copy of the aircraft record on a CD for $10 on-line at to review the record for outstanding liens yourself. However, this is no guarantee that a lien will be shown on the CD that you buy, especially if it’s a new lien. Keep in mind that the Aircraft Registration Branch does not do lien searches. For additional piece of mind you should contact a private company to do the search for you. Under “AC Form AFS-750-55, List of Title Search Companies” you can find a list of companies and law offices that provide lien searches for a fee.

If you have any further questions, please contact the Aircraft Registration Branch directly at 405-954-3116 or 866-762-9434. There are Legal Instruments Examiners on duty from 7:30 a.m. to 3:30 p.m. CST to answer your questions.

When I was a student pilot I did buy renters insurance for a little while, but sometimes I felt that flying was expensive enough so why add salt to the wound? The truth is that unless you have the FBO or Flying Club policy in your hand and you know for a fact that the premium is PAID and the policy is current and up-to-date, you are assuming too much risk. As 2012 approaches it might be time to re-think this behavior and opt for more protection. Here is some useful information from the AOPA Insurance site located at: http://www.aopaia.com

Aircraft Renter’s Insurance: Don’t take off without it.

This insurance is for your personal and non-commercial use of non-owned fixed wing, non-pressurized, land aircraft having a non-turbine single engine of 450 horsepower or less (including non-powered sailplanes) and capacity of no more than seven (7) total passengers and/or seats (1 pilot and 6 other passengers), and a standard, experimental, restricted, or light sport aircraft certificate, and not furnished to you for more than thirty (30) consecutive days. Multi-engine and rotor wing aircraft are not included in this coverage. For multi-engine and rotorwing nonowned coverage, please contact AOPA Insurance Agency at 1-800-622-2672.

Why should I buy a non-owned policy? My FBO tells me they have coverage.

FBO has coverage for them. Some FBO policies have provisions which will cover students and renters for liability coverage and provide a waiver of subrogation, but without seeing a copy of the policy you will never know what rights you have (if any) under the FBO’s policy. You are much better off having your own coverage.

What is non-owned liability coverage?

It is a liability insurance policy to protect you against claims arising from bodily injury and property damage for which you are legally liable, caused by an occurrence arising from your use of a non-owned aircraft. This coverage does not apply to the non-owned aircraft you have borrowed or rented. Physical Damage to your non-owned aircraft must be purchased.

I do not rent aircraft, but occasionally I borrow an aircraft from a close friend. I am named on their policy as an approved pilot, don’t I have coverage?

The policy is intended to cover the owner of the aircraft not the user of the aircraft. Depending on the policy and insurance company you may be held responsible to any damage you cause to the aircraft.

Will a non-owned policy provide coverage for a borrowed aircraft that doesn’t have insurance?

If you purchase physical damage to your non-owned aircraft coverage, the policy will provide you with liability coverage while using someone else’s aircraft. Your non-owned coverage is not a substitute for the aircraft owner buying their own coverage to protect their interests.

What type of aircraft am I permitted to use if I purchase a non-owned liability policy?

Non-owned coverage is for your personal and non-commercial use of non-owned fixed wing, non-pressurized, land aircraft having a non-turbine single engine of 450 horsepower or less (including non-powered sailplanes) and capacity of no more than seven (7) total passengers and/or seats (1 pilot and 6 other passengers), and a Standard, Experimental, Restricted or Light Aircraft Certificate, and not furnished to you for more than thirty (30) consecutive days.

Does the AOPA Insurance Agency offer any type of insurance for rotorcraft or multi-engine aircraft?

Non-owned coverage is available for multi-engine and rotorwing aircraft, however, it is not available through the website. Please call the AOPA Insurance Agency for more information about these products at 1-800-622-2672.

What limits of bodily injury and property damage liability should I carry?

There is no standard recommended amount of liability coverage you should carry. You need to consider factors such as your personal assets, earnings, whom you carry as passengers, and how much insurance you can afford or that is available. We recommend buying the most coverage you can reasonably afford and that is available.

What limits of aircraft damage liability should I carry?

For non-owned physical damage coverage, it depends on the value of the aircraft you typically rent and whether or not you want to fully be covered in the event of a total loss.

Does my immediate family or I have protection if we’re injured?

This policy covers bodily injury to others including immediate family, but does not include the named insured on the policy.

Is there a deductible on the aircraft damage liability coverage?

Non-owned coverage does not have a deductible.

What effect does pilot experience have on non-owned insurance premiums?

None. Premiums are based on the limits of coverage you select.

Who should purchase a non-owned policy?

Any pilot who rents or borrows someone else’s aircraft should purchase a non-owned policy. Even if you are receiving dual flight instruction and not acting as pilot in command in a non-owned aircraft, you may be held responsible for any damages or injuries arising from your negligence.

When should I purchase a non-owned policy?

We recommend you purchase a non-owned policy as soon as you start your flying lessons. You may be held legally liable for any losses that may occur.

Will a non-owned policy protect me if I use a non-owned aircraft for other than my own pleasure and business use?

No. Non-owned policies do not provide coverage if the non-owned aircraft is being used for or in connection with:

Aerial advertising, towing, photography or connection with; hunting, herding or spotting of animals of any kind, including birds and fish; patrol or surveillance of any kind, including powerlines, pipelines, traffic or fires; skydiving or parachuting; closed course racing; flights off-shore in support of fan off-shore business or operation; external transportation of persons or property, including wire stringing, or construction.

My employer allows me to rent aircraft to travel on company business, can you cover my employer on the non-owned policy?

Your employer may be added as an additional insured under the non-owned policy

What payment plans are available?

We require annual payment at the time the policy is bound. You can purchase your policy online at www.aopaia.com with a credit card or pay with a check with your application by mail or phone 1-800-622-2672.

What is the term of a non-owned policy?

One year.

If I have a non-owned policy and I later decide to purchase my own aircraft, can I cancel my non-owned policy?

Yes. As a result of destruction to tangible property to others, loss of use is covered.

Does a non-owned policy provide coverage for losses in excess of the limits on our flying club’s policy?

This insurance is excess insurance. If there is other insurance available to you, it will apply first.

Does your policy have any exclusion against landing on a private grass strip?

NO. However, the policy does exclude coverage when the non-owned aircraft is operated into, on or from an area that is not designed, maintained and used as an airport except a landing due to a recorded emergency. This exclusion will not apply to a forced landing due to emergency flight conditions.

Can I fly outside the continental US?

The non-owned policy covers flights within the political boundaries of the United States of America, Mexico, Central America, Canada, the Islands of the West Indies (excluding Cuba), and while enroute between places therein.

I am a CFI – Why do I need a non-owned policy?

The Comprehensive CFI policy covers your negligence arising from your personal use of non-owned aircraft, covers your negligence while instructing in non-owned aircraft and provides coverage for claims that may arise out of your professional liability as a CFI. Although few have been sucessful in suing a CFI for their bodily injury or property damage arising from alleged negligent instruction the Comprehensive CFI policy provides you with defense coverage (legal fees) which can add up to hundreds of thousands of dollars.

I fly for the CAP – Does your policy cover this?

Yes – an endorsement can be added to the policy to cover CAP flights.

I am not interested in liability protection, can I only purchase the liability for aircraft physical damage option?

No – The company will only package the policy with liability for bodily injury, property damage and physical damage to non-owned aircraft. You may purchase liability for bodily injury and property damage only though.

My spouse is learning to fly as well, can I add him/her to my policy?

The non-owned policy covers only one individual, your spouse must buy their own policy to cover their use of non-owned aircraft.